And still more about the (still not) leaking Macondo Well…

The truth is so...the truth, well, it can just be so...messy.

Ed. Note: Times Picayune now reporting investigators from both BP and the Coast Guard have gone out to the well site and found nothing. BP plans to send a ROV down to the seafloor tonight to determine if the well is leaking. Also, tests on the oil sheen spotted by Press-Register reporters has come back as a match to the oil that spilled last year. So, according to USCG and BP, no oil today, but the oil yesterday is a match to the Macondo…I feel better?

Reporters from the Alabama Press Register were out on the water near the Macondo Well site to investigate reports, floating around for over a week now, about new oil sheens on the Gulf’s surface:

“The Press-Register reporters located the area where the oil was rising to the surface by going to a point directly over the Macondo well and then moving in the direction of the prevailing surface current. The first blobs of oil seen on the surface were detected about a half-mile from the well. The frequency of the sightings increased gradually over the next half-mile.

In the Olympic swimming pool-sized area where the oil was rising most frequently, new sheens were erupting every few seconds on all sides of the 36-foot boat.

Marcus Kennedy, who piloted his fishing boat, the Kwazar, 115 miles from Dauphin Island to the well site, said he was stunned by the heavy petroleum scent in the air. A nearby data buoy recorded winds of less than 2 mph at the time”

Now, reports differ on where this oil is coming from:

BP, of course, denies this has anything to do with the Macondo Well.

Phillip Johnson, a professor at the University of Alabama feels the oil is most likely residual, just oil leaking from the 5000 feet of riser pipe left on the sea floor or oil that had been trapped in various debris from the sunk platform that’s now worked its way free.

Ed Overton, an oil chemist, feels more investigation is needed, to find out what is going on, “There is no way to say for sure whether the well is leaking, based on what is on the surface,” he said. “Of course it is suspicious.”

The Coast Guard has determined the leakage is from natural seeps and permitted pollution releases at other drilling sites, but did not elaborate how this was determined, and said no boats had been out near the well location.

Robert Bea, professor emeritus at UC-Berkeley, after looking at photographs of the sheen said, “I think the primary source with high probability is associated with the Macondo well…perhaps connections that developed between the well annulus (outside the casing), the reservoir sands about 17,000 feet below the seafloor, and the natural seep fault features” could provide a pathway for oil to move from deep underground to the seafloor, Bea said.

Lot of opinions, lot of oil, lots of possible narratives…

What’s needed is the truth.

Perhaps along with that GCCF audit, US Attorney General Eric Holder might find an independent investigator to get ahead of this story now, find out what, if anything is going on in the Gulf, throw a wrench in the spin cycle and beat that dryer to hell. When the Deepwater Horizon went down 16 months ago, the information appeared immediately slanted to fit a damage control agenda, truth be damned…so much so the Justice Department is now investigating BP for faulty oil spill estimates.

Not that we are headed for a repeat, but it might be nice this time, to start any sort of response to these sheens from the basis of truth.

Where are the sheens coming from? Is it likely there will be more? Is it coming from the Macondo Well?

Is there something wrong with the seal, with the sea floor?

Hopefully not.

But I’d sure like to know…regardless of whatever anyone who might stand to lose public relations battles or profit thinks about it.

“Last week, in response to Internet postings by lawyers and environmental groups describing a leak, BP issued a blanket denial, stating, “None of this is true.””

A blanket denial from British Petroleum, with little to no explanation.

Even if they are right, a blanket denial is not good enough, not this time.

2 thoughts on “And still more about the (still not) leaking Macondo Well…”

Macondo MC 252 is in an area of severe geological hazards, including gas hydrates and weak shallow (< 5,000 ft) artesian pressurised sand layers which can cause casing distortion and even buckling collapse, high inflow of drilling fluids, washout and partial collapse of those layers due to rapid drilling disturbance.
This “geohazard” is known as “shallow water flow” [SWF] and the associated risks have been extensively reported in the technical literature, and ranked and mapped by the MMS. The presence of frozen gas hydrates along the Mississippi Canyon continental shelf edge is well known.
Despite all the above, BP took the decision to continue to attempt to drill the one of the world’s deepest wells to date in a slapdash, corner-cutting, driving down cost, “maximise added” value fashion.
With proper drilling design, control and cementing, wells have been completed under these conditions in the past. However the risks should always be thoroughly assessed, with appropriate prevention and mitigation techniques and controls in place. Such measures are also well documented based upon the past experiences of GoM operators, including BP.
Indications are that the drillstring was fractured/damaged as a result of SWF drilling fluid fracture, washout and collapse over a certain depth interval. Severe problems and drilling mud losses were recorded at the time. The expanded pressurised melted hydrate gas may have blown through the damaged casing and weak pathways in the bad cement job following the final negative leak off test. Drilling mud was displaced by seawater over too great a depth, leading to reduced internal hydrostatic pressure and a sudden imbalance between the internal (fluid) and external (gas in sand) pressures. The hydrate melted around the casing due to heat given off by the curing cement.
The subsequent upwards rush of gas probably caused a siphoning effect down onto the bottom of the casing (shoe) which then breached the control barriers at the bottom and reservoir hydrocarbons were pulled upwards rapidly.
A recent very detailed DNV forensic report on the BOP failure leads to the conclusion that a BOP would have failed even if it had been in perfect condition, due to the condition of the well, it’s out of vertical alignment and the sudden immense force of the gas and fluid flow.
The question that should be asked is: where did that huge quantity of gas come from? Calculations may show that the valve system at the bottom of the well is unlikely to have “somehow” failed as a result of pressure changes far up the drillstring, causing a sudden influx of a vast quantity of gas from the hydrocarbon reservoir some two and half miles below seabed to burst upwards through fairly dense drilling mud at such a high velocity.
Consideration of the temperature and pressure regime in the shallow hole section below seabed suggests that natural in-situ hydrates are very likely to have been present at the Macondo location over a depth interval of a few hundred metres below mudline. The heat generated as a result of cement curing is likely to have led to melting of section of this natural hydrate bearing zone some distance radially from the cement and a subsequent increase in pressure as the gas tried to expand within one or more of the known SWF sand layers. The presence of channels at certain levels within the cement is likely to have permitted a pathway(s) to form along part(s) of the 16” casing. Due to possible earlier drilling disturbance of the known layers of Shallow Water Flow [SWF] sands prior to the melting of the hydrates, the 16” casing may have been out-of-straight or even slightly buckled as a result of partial liquefaction and softening of the SWF sands (similar to that observed at URSA in 1999 in the GoM). This loss of lateral support may have caused a crack or breach in the casing, or a loosening at the casing joint(s). This casing is suspected to have been of too low a yield strength for the well design. At the point during the negative leak-off test when the pressure differential became sufficiently high, it is well documented and accepted that the three “burst disks” placed at certain points on the casing joints down the casing string blew out at their inwards blowing rated burst pressure of 7500 psi. At this point the large pressure drop occurring within the mud fluids in the annulus between the production casing and the 16” casing might have been sufficiently dramatic to allow a rapid influx of trapped pressurised gas lying within the SWF sand(s) and in the pathways worked within the cement. This build up may have caused a very high pressure jet to blow out some or all of the rupture disks in the 16” casing, if the pressure differential between the seawater filled production casing and the annulus on the other side were sufficiently high. This gas would have travelled very quickly up the production casing, siphoning water, mud and subsequently oil with it as the production casing shoe was blown due to the very high suction force exerted upon it.